1. Field of the Invention
The present invention relates to a cylinder reciprocation control apparatus capable of shortening time required to switch the direction of reciprocation in a cylinder and improving the durability and a ring alignment apparatus using such a cylinder reciprocation control apparatus to align and holding a plurality of ring members each having a gap upstanding in a continuous manner.
2. Description of the Prior Art
In the prior art, means for reciprocating a cylinder a includes a two-position type four-port electromagnetic valve b for switching the cap and head sides of the cylinder a with respect to air delivery and exhaust, as shown in FIG. 18. Such a four-port electromagnetic valve b has its response speed retarded through reciprocation of various movable parts such as spool, poppet and others. In addition, more time is required to perform the air delivery/exhaust operation relative to the cap and head sides of the cylinder a. Time required to reciprocate the cylinder a through one cycle is a minimum of about two seconds. Furthermore, the four-port electromagnetic valve b is disadvantageous in that it is of a complicated structure including solenoids, spool, poppets and others and has less durability.
In the prior art, means for aligning and holding ring members upstanding is in the form of a block member including a plurality of grooves formed therein and spaced away from one another in the longitudinal direction. Ring members are manually fitted into the respective grooves in the block.
It is therefore an object of the present invention to provide a cylinder reciprocation control apparatus which can easily and simply vary the reciprocation repeating cycle and reduce time required to switch the direction of reciprocation in the cylinder with an improved durability.
Another object of the present invention is to provide a ring alignment apparatus which can easily and simply be automated to align and hold a plurality of ring members upstanding with an improved operativity.